Author's Note:

I would like to thank everyone who has been reading these challenges is another the 'Event' crossover challenge. In this story Kai and Ben try to go up against the newly formed power group (Charmcaster, Sunny, and Elena) after they kill Ben and Kai's love ones. However they are transported to the charmed universe by accident. Also, I am trying to keep the story cannon wise with

Ben 10 Charmed Challenge Summary:

After failing to stop the combined powers of three powerful enemies (Charmcaster, Sunny, and Elena) Ben and Kai are transported to the charmed universe the moment phoebe casted the spell to restore the sisters powers. Now trapped and nowhere to go Ben must now serve as the charmed ones guardian while surviving a in a new and magical world and repair his relationship with Kai.

General Rules:

- Takes place after Omniverse

- Ben and Kai are 20.

- Kai has Excalibur and is protected in some way from demon acts.

- Kai and Sandra blames Ben for Kai greens and Carl Tennyson deaths.

-Ben must be more mature than he is in Omniverse, but can show humor.

-Phoebe must want bens omnitrix powers, or show envy towards Ben for the first two seasons.

-Must contain main pairings (PureXAndy) (PiperXLeo)(PheopeXCoop)(PaigeXHenry), however they may date as normal though out the show.

-The following are killed Carl Tennyson, Frank Tennyson, Lily Tennyson, members of Rooks family, and West Green.

-Paige must not be introduced until season 4.

-The omnitrix is linked to the book and the charmed ones.

-Also Ben can turn into White Lighter, Avatar, Elder, Demon, Warlock etc. and when a Demon and Warlock is vanquished the corresponding form increases in power.

-Ultimate Forms and master control can be introduced, but only as the series progresses (However, master control may be unlocked temporally from time to time).

-Also, Ben can work on creating the bio-matrix as the series progresses.

-Paradox and everyone of bens universe do not find out where he is at until tempus powers active at the end of season one.

-The charmed ones can go with Ben to his universe from time to time.

-The charmed ones can also have omnitrixes, but after season 4.

Evil Power of Three Rules

-Gwen can have her powers stolen by the three, but must not be killed.

-Also, they can drain the powers of the six Charms of Bezel, Hex's Staff, and the Alpha Rune

-The three will steal some power from vanquished demons.

-They can collect power from powerful supernatural creatures of other Fictional series (Examples: Diablo, Devil May Cry, Silent Hill, Resident Evil, Inuyasha, Fullmetal Alchemist, Rosario + Vampire, etc) to become the power of 30,000.

-After Season 1 the evil power of three can send enemies of Ben either Deceased or Living to the charmed Universe to learn more about the Charmed Ones.

Rules and ideas by season

Season 1

-When Ben is brought back the omnitrix will be affected every time a charmed one touches it (all three must touch it in the first episode.) and the effects vary depending on how many touch it.

-One: the omnitrix transformations are 'magical' and 'monster alien forms'

-Two: The omnitrix is stuck in recalibration mode until the third charmed one touches it.

-Three: The omnitrix is recalibrated with a new look and is fully linked to the book.

-Andy is killed at the end of season one and cannot be brought back until season 4.

Season 2

-Phoebe wishes for an omnitrix in the season 2 final.

Season 3

-(An Idea: Sandra can visit Ben in Once Upon a Time, but Ben and the sisters try to hide their magic secret from her because Sandra thinks Ben is done with the hero business for good and living a more 'normal life'. However, Sandra becomes suspicious of Ben and the sisters before finding out when Abby kidnaps her with Pure in Sight Unseen.)

-Kenny can be conceived this season or next season.

-See season 4 for Pure.

Season 4

-When Pure dies she must be brought back by Alien X (However Paradox takes Ben before he can turn into Alien X to convince the Elders to allow Alien X to create a power of five with the omnitrix stabilizing the power of five (The main reason is Gwen). This last until the end of Hell have no fury.)

-When the elders agree they will allow Prue to be brought back with an omnitrix, but cannot be allowed to see her sisters for a year.

-While Ben is speaking with the elders; Kevin, Ester, Kai, Rook, Rook Ben, Ben 23, Clyde Fife, or Lucy Munn must serve as a substitute guardian.

-Also, the substitute guardian can prevent Cole from savaging his white wedding.

-If Cole and Phoebe are married in a white wedding, Paradox can safe Phoebe's unborn child by switching him with an evil version. However the baby must be put up for adoption in Ben's World.

Season 4 (Prue's Side)

- Pure will obtain an omnitrix and will operate in Ben's universe until phoebe turns evil.

- Pure must feel bitter towards Paige due to her 'replacing' Pure until 'Sympathy for the Demon'.

- Pure can have Andy as her white lighter.

- Pure can have Ben's current aliens or a different set of aliens.

- You can create any stories you want.

Season 5 &6

-(Idea: Chris can come back in time the first or second time with Gwendolyn (Ben and Kai's daughter) and/or Prue and Andy's Daughter (Who is Part Witch, Part White Lighter, and Part Avatar. Also, she is one of three of Prue and Andy's kids and part of the immortal power of three).

-Future Wyatt can be at War with the evil power of three and have any form of Omnitrix.

-Chris along with anyone else he brings back can have an Omnitrix but must hide them (They can hide them with Ultimate Versions of themselves similar to Ultimate Ben).

-If Pure's daughter is introduced than Pure must be pregnant between Spin City and the end of season 6.

Season 7

-Pure gives birth after becoming an Avatar if impregnated last season.

-Also, Pure can remain an Avatar as a punishment.

-Optional: Kai can become an Avatar.

-When the Charmed One's fake their deaths they will hide in Ben's World for a while.

Season 7.5

-This is a season dealing with the Evil Power of three however this can take place between season 8 and 9.

-You can create any story in this season.

-Also Demon's and other supernatural creatures.

-Members of the Evil Power of three must be defeated and can be killed, imprisoned, or stripped of her powers.

-The Charmed Ones and Ben must return to the Charmed Universe.

Season 8

-Christy can be saved.

Season 9 & 10

-Christy or Billie Substitutes Prue's Role at the end of Season 9 & all through season 10.

-The Charmed World can know about magic and both Ben 10 and the Charmed Worlds can be linked via tears in reality.